Critical overview of Rheocasting Technologies

A quick patent search brought up 87 different Rheocasting technologies from the last 30 years. Most of them never left the laboratories that created them. Three technologies are still around.

GISS, SEED and RheoMetal. GISS and SEED work by a temperature controlled cooling process. This the critical weakness of these two technologies. If you want a steady process with same slurry parameters at every shot, to only possibility is the have the melt chemistry fixed. In the picture below you see the Al-Si phase diagram. Even a small change in the silicon level results in a different liquidus temperature. Also Iron, Magnesium, Manganese, Strontium have an influence on the liquidus temperature. This creates a 5 or more dimensional phase diagram. When cooling to the same temperature you will end up at different slurry and therefore casting parameters every time you refill the holding furnace. Then you have to find the parameters for that exact chemistry. Considering normal variations in chemistry changes at a foundry, these adjustments are not feasible in series production foundry.

RheoMetal works by melting of an Aluminum “ice cube”. The ice cube is called EEM (Enthalpy Exchange Mass). It is freshly produced from the same melt as the shot weight. So it has the exact same chemistry and solidification behavior. Therefore, normal changes of the melt chemistry within a foundry does not affect the slurry characteristics. This results a stable production process with consistent casting quality.

In HPDC only a casting process that can deliver constant high quality cast parts throughout the series lifetime is one that earns a living for everyone involved. The mentioned production stability of the RheoMetal process delivers exactly that to foundries. That is the key reason why Casting-Campus GmbH partnered with Comptech AB.

When you want to learn more about Rheocasting and how it can bring new business to your foundry, schedule your free consultation down below.